Conventionally, an example of a technology related to a rotation detecting unit which can deal with increase in the types of integrated circuits (IC) for rotation detection at low cost is widely known (see, for example, JP-A-2005-172573 corresponding to US2005/0126308A1). This rotation detecting unit includes a shape adjustment part, which is molded from resin to cover a rotation detecting part, to conform a shape of a rotation detecting part to an internal shape of a housing.
Moreover, an example of a technology related to a magnetism quantity variation sensor for improving accuracy of a position of a magnetoelectric transducer at the time of covering of resin molding is widely known (see, for example, JP-A-2005-227095). According to this magnetism quantity variation sensor, there are at least two positions at which a lead terminal in a shape of a linear plate piece is engaged with a holder of the magnetoelectric transducer, and a thickness direction and width direction of the lead terminal are positioned respectively at two places or more. Then, all of these are covered with resin molding.
However, according to the technology described in JP-A-2005-172573, low-pressure molding (hot melt) for protecting the IC and the joint region from a molding pressure of the main body, after joining together a wire and IC by welding to form a main body part is necessary. In addition, the housing is necessary as a component for the positioning fixing of the IC and a seal of the main body. Because polybutylene terephthalate (PBT) which is a thermoplastic resin is used for the main body resin, there is no adhesive strength with respect to a core wire. For this reason, forming is required for the wire part to secure wire fixing force and to absorb displacement at the time of molding. Accordingly, a size of the rotation detecting unit cannot be reduced.
According to the technology described in JP-A-2005-227095, all of these are covered with resin molding with the lead terminal engaged with the holder of the magnetoelectric transducer. Thus, the magnetism quantity variation sensor has such a size that includes the holder. Accordingly, the size of the entire magnetism quantity variation sensor cannot be made smaller than the size of the holder.